Abstract: The present paper deals with the effects of aluminium chloride solution in different concentrations on the root growth, the cell division of root meristem and the chromosomal morphology of Allium cepa.The results showed:the rate of the root growth decreased progressively with increase of A13+ concentration; the speed of the root growth per time unit also decreased progressively even though growth stopped with the increase in the duration of treatment; Treated with 50-200ppm aluminium chloride to Allium root, the mitotic index decreased progressively with increase of A13+ concentration and the treatmeent duration; different concentrations of the treatments with Al³⁺ could induce chromosomal aberration; after the recover culture, the bulbs of the onion in all the treatments could grow and the rate of chromosomal aberration decreased.

Key words: Aluminium chloride, Allium cepa, Mitosis, Chromosomal aberration